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Homework Help: Counterweight in An Elevator System

  1. Jan 11, 2012 #1
    An elevator system, includes a cabin of 2000 kg, a counterweight of 2220 kg and a load of 550 kg, moves at constant speed) of 1.75 m/s upwards. Find the power being delivered to the system including only the cabin and load. (Take g, acceleration of gravity = 10 m/s^2)

    *The counterweight helps save energy, as the loss in G.P.E. itself goes to part of the gain in G.P.E. of the cabin and load.

    The answer given by my textbook is 5775 W. However my teacher says it should be 44625 W, and I don't know which one is correct, please help me!
  2. jcsd
  3. Jan 11, 2012 #2

    Doc Al

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    Staff: Mentor

    Your instructor failed to consider the work done by the counterweight. The wording of the problem is ambiguous: what does 'including only the cabin and load' mean? If they didn't want you to consider the effect of the counterweight, why mention it?
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